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JAEA Reports

Results of single borehole hydraulic tests in the Mizunami Underground Research Laboratory Project (FY2016 - FY2019)

Onoe, Hironori; Takeuchi, Ryuji

JAEA-Data/Code 2020-011, 50 Pages, 2020/11

JAEA-Data-Code-2020-011.pdf:2.44MB

This report summarize the results of the single borehole hydraulic test carried out at the -300 m Stage and the -500 m Stage of the Mizunami Underground Research Laboratory from FY 2016 to FY 2019. The details of each test (test interval depth, geology, etc.) as well as the interpreted hydraulic parameters and analytical methods used are presented in this report. Furthermore, the previous results of the single borehole hydraulic tests carried out in the Regional Hydrogeological Study Project and the Mizunami Underground Research Laboratory Project before FY 2016 are also summarized in this report.

Journal Articles

A Measurement method of long-term mechanical stability of support and rock mass after the excavation of galleries; Case study in Horonobe Underground Research Center

Aoyagi, Kazuhei; Sakurai, Akitaka; Miyara, Nobukatsu; Sugita, Yutaka; Tanai, Kenji

Shigen, Sozai Koenshu (Internet), 6(2), 7 Pages, 2019/09

no abstracts in English

Journal Articles

Application of the transient pulse method to measure clay permeability

Kato, Masaji*; Nara, Yoshitaka*; Okazaki, Yuki*; Kono, Masanori*; Sato, Toshinori; Sato, Tsutomu*; Takahashi, Manabu*

Materials Transactions, 59(9), p.1427 - 1432, 2018/09

 Times Cited Count:2 Percentile:74.82(Materials Science, Multidisciplinary)

To ensure the safe geological disposal of radioactive waste, it is important to determine the permeability (hydraulic conductivity) of clays. The transient pulse method is suitable for low-permeability materials because it requires a relatively short time to determine their permeability. Upstream pore pressure typically increases in the measurement conducted via the transient pulse method. However, this procedure cannot be used to determine the permeability of clays due to the increase in pore pressure. Therefore, the transient pulse method has never been applied to determine clay permeability. In this study, we applied the transient pulse method to a clay sample to determine its permeability while decreasing the downstream pore pressure.

JAEA Reports

Study on characterisation of colloidal silica grout under condition of sea water

Toguri, Satohito*; Okihara, Mitsunobu*; Tsuji, Masakuni*; Nakashima, Hitoshi*; Sugiyama, Hirokazu*; Saito, Akira*; Sato, Toshinori; Aoyagi, Kazuhei; Masunaga, Kosuke

JAEA-Research 2017-013, 131 Pages, 2018/02

JAEA-Research-2017-013.pdf:8.49MB

The discussions on scientifically promising site for the geological disposal has been made at the council of studying group on techniques for geological disposal of radioactive wastes, which is held by Resources and Energy Agency. From the aspect of ensuring safety during the transportation of disposal waste, the coastal area is discussed to be a more suitable area. This report shows the result of the first year of this project as following items; Study on the state-of-art technology and remain tasks; laboratory tests on characterization of colloidal silica grout under sea water; Study on the development of grouting technology (design and the evaluation method of influence on the rock mass).

JAEA Reports

Measurement of rock mass deformation around the closure test drift during groundwater recovery experiment at 500m depth of Mizunami Underground Research Laboratory

Kuwabara, Kazumichi*; Aoyagi, Yoshiaki; Ozaki, Yusuke; Matsui, Hiroya

JAEA-Research 2017-002, 39 Pages, 2017/03

JAEA-Research-2017-002.pdf:3.58MB

Authors developed a displacement meter using optical fiber sensor. The displacement meter can be set at any locations in a borehole and guarantee the measurement accuracy up to 5MPa. Total twelve displacement meters were installed in three boreholes to measure the rock mass displacement during groundwater recovery test. The measurement of the rock mass displacement was stated on March, 27, FY 2014. During the first and second groundwater recovery experiments, compressive displacements were observed close to the closure test drift wall. Magnitude of the measured displacements, except vicinity of test drift wall, was smaller than that of calculated under the assumption of it is an isotropic elastic material.

Journal Articles

Evaluation of fractures in a rock as flow paths around tunnel using ground penetrating radar

Masumoto, Kazuhiko*; Takeuchi, Ryuji

Oyo Chishitsu, 57(4), p.154 - 161, 2016/10

Fractures developing around the tunnel during the excavation result in issues related not only to the mechanical stability of the rock cavern, but also to the groundwater flow paths. In order to estimate the possibility of application of the GPR (Ground Penetration Radar) to estimate the fractures as low paths, the authors conducted the GPR survey along the side wall of 500 m access tunnel of the Mizunami Underground Research Laboratory of JAEA. The results of the profile measurements indicated that water-conductiong fractures were detected as a reflected waves using GPR survay. Furthermore, as the results of fixed-point measurements during the injection of the saline water, it could be indicated to estimate the flow paths of saline water in the fractures, in a non-destructive way, based on spectral analysis in the reflected waveforms of GPR.

JAEA Reports

Annual data compilation of water balance observation in the Mizunami Underground Research Laboratory Project (MIU Project); For the fiscal year 2013

Ueno, Tetsuro; Takeuchi, Ryuji

JAEA-Data/Code 2015-007, 55 Pages, 2015/06

JAEA-Data-Code-2015-007.pdf:9.53MB
JAEA-Data-Code-2015-007-appendix(CD-ROM).zip:194.09MB

Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has carried out the subsurface water balance observation in order to estimate groundwater recharge rate for setting the upper boundary conditions on groundwater flow simulation and to obtain data for calibration of hydrogeological model. In the subsurface water balance observations, meteorological data, river flow rate, groundwater level and soil moisture have been observed in the Shoma River watershed, the Shoma River model watershed and the MIU Construction Site. After missing or abnormal data in the monitoring data from the fiscal year 2013 were complemented or corrected, the data were compiled in data set. Furthermore the groundwater recharge rates in the Hazama River watershed were calculated using the river flow rate data obtained from the environment survey in the MIU construction work in the fiscal year 2013.

JAEA Reports

Annual data compilation of water balance observation in the Regional Hydrogeological Study Project (RHS Project); For the fiscal year 2013

Ueno, Tetsuro; Takeuchi, Ryuji

JAEA-Data/Code 2015-006, 22 Pages, 2015/06

JAEA-Data-Code-2015-006.pdf:5.05MB
JAEA-Data-Code-2015-006-appendix(CD-ROM).zip:14.52MB

Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has carried out the subsurface water balance observation in order to estimate groundwater recharge rate for setting the upper boundary conditions on groundwater flow simulation and to obtain data for calibration of hydrogeological model. In the subsurface water balance observations, precipitation data and river flow rate have been observed in the Garaishi River and the Hiyoshi River watersheds. The missing or abnormal data in the monitoring data during the fiscal year 2013 were complemented or corrected, and these data were compiled in data set.

JAEA Reports

Mizunami Underground Research Laboratory Project; Rock mechanical investigations annual report for fiscal year 2013

Sato, Toshinori; Sanada, Hiroyuki; Tanno, Takeo*

JAEA-Review 2014-049, 34 Pages, 2015/02

JAEA-Review-2014-049.pdf:26.38MB

This report presents the results of following rock mechanical investigations conducted in FY 2013. In-situ stress measurements using Compact Conical-ended Borehole Overcoring Technique were performed at the - 500m stage. Measurement system for rock mass displacement using optical fiber was installed at the - 500m stage as one of the reflooding test. Study on the modeling based on equivalent continuum model was continued. Phenomenological study and theoretical study on long-term behavior of crystalline rock were continued. Additionally, joint research, "Study on estimation of in-situ rock stress based on the results of various measurements" with Tokai University was also performed.

JAEA Reports

The Arrangement of the seismic design method of the underground facility

Tanai, Kenji; Horita, M.*; *; Goke, Mitsuo*

JNC-TN8410 2001-026, 116 Pages, 2002/03

JNC-TN8410-2001-026.pdf:9.19MB

Earthquake resistance for the underground structure is higher than the ground structure. Therefore, the case of examining the earthquake resistance of underground structure was little. However, it carries out the research on the aseismic designing method of underground structure, since the tunnel was struck by Hyogo-ken Nanbu Earthquake, and it has obtained a much knowledge. However, an object of the most study was behavior at earthquake of the comparatively shallow underground structure in the alluvial plain board, and it not carry out the examination on behavior at earthquake of underground structure in the deep rock mass. In the meantime, underground disposal facility of the high level radioactive waste constructs in the deep underground, and it carries out the operation in these tunnels. In addition, it has made almost the general process of including from the construction start to the backfilling to be about 60 years (Japan Nuclear Fuel Cycle Development Institute, 1999). During these periods, it is necessary to also consider the earthquake resistance as underground structure from the viewpoint of the safety of facilities. Then, it extracted future problem as one of the improvement of the basis information for the decision of the safety standard and guideline of the country on earthquake-resistant design of the underground disposal facility, while it carried out investigation and arrangement of earthquake-resistant design cases, guidelines and analysis method on existing underground structure, etc.. And, the research item for the earthquake resistance assessment of underground structure as case study of the underground research laboratory.

JAEA Reports

Dataset of the relationship between unconfined compressive strength and tensile strength of rock mass

Sugita, Yutaka; Yui, Mikazu

JNC-TN8450 2001-007, 16 Pages, 2002/02

JNC-TN8450-2001-007.pdf:0.78MB

This report summary the dataset of the relationship between unconfined compressive strength and tensile strength of the rock mass described in supporting report 2; repository design and engineering technology of second progress report (H12 report) on research and development for the geological disposal of HLW in Japan.

JAEA Reports

The Planning of future research program of underground laboratories in overseas

*; Tanai, Kenji; *

JNC-TN8420 2001-007, 86 Pages, 2002/02

JNC-TN8420-2001-007.pdf:6.04MB

The objectives of this study is to identify the research issues, which are to be conducted in the future underground research laboratory, about operation and logistics systems for the planning of future research and development program. The research programs and experiments,etc. were investigated for the geological disposal projects in overseas sedimentary rocks and coastal geological environments aiming to reflect in the future underground research facility plan in Japan. In the investigation, information on the engineered-barrier performance, design and construction of underground facilities, tunnel support, transportation and emplacement, and backfilling technology, etc. were collected. Based on these informations, the purpose, the content, and the result of each investigations and tests were arranged. The strategy and the aim in the entire underground research facility, and the flow of investigations and tests, etc. were also arranged from the purpose, the relations and the sequence of each investigation and experiment, and the usage of results, etc.

JAEA Reports

A Study of structure of base-isolated

; ; Yamazaki, Toshihiko; ; ; Kondo, Toshinari*; *

JNC-TN8400 2001-030, 99 Pages, 2002/01

JNC-TN8400-2001-030.pdf:13.24MB

There is a great deal of that we build a Base-Isolated building with the quaternary deposit ground. In an atomic energy institution, a study request is strong. When we build a Base-Isolated building with the quaternary deposit ground, evaluation of earthquake vibration of a vertical direction is an important problem. In an atomic energy institution, we design it by big earthquake load, and therefore examination is necessary. And, in this study, we do examination to build a Base-Isolated building with the quaternary deposit ground, we report it about an evaluation method of a design. Furthermore, we report that we estimated pipe laying and machinery to put in a building of Base-lsolated.

Journal Articles

Study on deep groundwater flow

Kumata, Masahiro; Mukai, Masayuki; Iwamoto, Hiroshi*

JAERI-Conf 2001-015, p.80 - 81, 2001/12

Based on the groundwater scenario, prediction of the transport of radionuclides from waste disposal facilities requires an understanding of deep groundwater flow system. Capabilities offering by isotope techniques using environmental tracer enable one to estimate past and present behavior of groundwater system, and therefore establish a basis for future predictions. A study area was selected in Japan and hydrogeological study has been performed. On the other hand, fractures in the hard rock mass play an important role on groundwater flow at the depth. Basic study was performed for resistivity tomography, one of the useful techniques for the evaluation of rock fractures.

JAEA Reports

Theoretical background and user's manual for the computer code on groundwater flow and radionuclide transport calculation in porous rock

*;

JNC-TN8400 2001-027, 131 Pages, 2001/11

JNC-TN8400-2001-027.pdf:0.8MB

In order to document a basic manual about input data, output data, execution of computer code on groundwater flow and radionuclide transport calculation in heterogeneous porous rock, we investigated the theoretical background about geostastical computer codes and the user's manual for the computer code on groundwater flow and radionuclide transport which calculates water flow in three dimension, the path of moving radionuclide, and one dimensional radionuclide migration. In this report, based on above investigation we describe the geostastical background about simulating heterogeneous permeability field. And we describe construction of files, input and output data, a example of calculating of the programs which simulates heterogeneous permeability field, and calculates groundwater flow and radionuclide transport. Therefore, we can document a manual by investigating the theoretical background about geostastical computer codes and the user's manual for the computer code on groundwater flow and radionuclide transport calculation. And we can model heterogeneous porous rock and analyze groundwater flow and radionuclide transport by utilizing the information from this report.

JAEA Reports

Long-term effect of creep displacement of host-rock on stability of engineered barrier system for TRU waste; Two-dimensional analysis by the non-linear viscoelasticity model

Aoyagi, Takayoshi*; *; Mihara, Morihiro; Okutsu, Kazuo*; Maeda, Munehiro*

JNC-TN8400 2001-024, 103 Pages, 2001/06

JNC-TN8400-2001-024.pdf:11.6MB

In the disposal concept of TRU waste, concentrated disposal of wastes forms in large cross-section underground cavities is envisaged, because most of TRU waste is no-heat producing in spite of large generated volume as compared with HLW. In the design of engineered barrier system based on large cross-section cavities, it is necessary to consider the long-term mechanical process such as creep displacement of the host rock from the viewpoint of the stability of engineered barrier system. In this study, the long-term creep displacement of the host rock was calculated using the non-linear viscoelasticity model and the effects on the stability of engineered barrier system was evaluated. As a result, in the disposal concept of crystalline rock, no creep displacement occurred at the time after 1 milion year. On the other hand, in the disposal concept of sedimentary rock, creep displacement of 80$$sim$$90mm occurred at the time after 1 milion year. Also, in this calculation, a maximum reduction of 45mm concerned with the thickness of buffer material was estimated. But these values resulted within allowance of design values. Therefore, these results show that the effects of the creep displacement on the stability of engieered barrier system would not be significant.

JAEA Reports

Sampling of rock block for water flow calibration on LABROCK

Uchida, Masahiro;

JNC-TN8410 2001-016, 36 Pages, 2001/05

JNC-TN8410-2001-016.pdf:1.53MB

This technical report summarizes sampling of the natural rock including conductive fracture. Hydraulic test was conducted at the target fracture prior to excavation. Objective of the sample was to reproduce same transmissivity at LABROCK by adjusting normal stress. This report was originally compiled by PNC in october, 1993.

JAEA Reports

Excavation and preparation rock block sample for LABROCK

Uchida, Masahiro;

JNC-TN8410 2001-015, 35 Pages, 2001/05

JNC-TN8410-2001-015.pdf:1.73MB

This technical report summarizes excavation and preparation of the natural rock block sample used in LABROCK. This report was originally compiled by PNC in March, 1993.

JAEA Reports

The data analysis of the single well injection-withdraw tracer experiment using the MACRO II

*; *;

JNC-TN8400 2001-012, 69 Pages, 2001/04

JNC-TN8400-2001-012.pdf:8.43MB

On understanding the radionuclide transport in natural barrier in radioactive waste isolation research, the macroscopic dispersion in heterogeneous permeability field in the underground rock is regarded as an important process. Therefore, we have conducted lots of tracer experiments by the MACRO II facility with an artificially constructed heterogeneous permeability field. In order to study the scale dependence of dispersion coefficients in case of laboratory experiments, we placed the flow cell horizontally, and conducted injection-withdraw tracer experiment with a single well. We have conducted I5 cases experiments. These cases were prepared by changing a position of single well and the injection-withdraw time. At each position we have conducted 9 cases and 6 cases experiments. In this report, we evaluated the macroscopic dispersion coefficients by the fitting of analytical solution to breakthrough curve measured by the 15 cases pumping tracer experiment. Consequently, we could evaluate the dispersion coefficients for 12 cases of 15 cases. Then, we discussed the relation between a injection-withdraw flow rate and a property of heterogeneous media and dispersion coefficient. The conclusions obtained from the results of the evaluation are summarized as follows, (1)It was found that the macroscopic dispersion coefficients tend to be increased with increase of the average radius of tracer front spread around a single well. (2)We have conducted any experiments with s single well settled at two positions. In case of that there is low permeability around a single well, we found dispersion coefficients are large. In case of that there is high permeability around a single well, we found dispersion coefficients are small. (3)In three cases that we could not evaluate because of incorrect accuracy of fitting, we have found it possible that there is some points that dispersion coefficients were strikingly small in tracer front.

JAEA Reports

Nuclide migration uncertainty study in channel network model approximation

; *

JNC-TN8400 2001-010, 25 Pages, 2001/03

JNC-TN8400-2001-010.pdf:0.65MB

Performance assessment in geosphere for the JNC's 2nd progress report was based on nuclide migration calculation results by discrete fracture network model. The channel network model approximated from fracture network model with considering fracture connectivity was applied for nuclide migration analysis, since fracture network model had too large data to calculate nuclide migration. However, there are many options in the process of approximation from fracture network model to channel network model. In case of analyzing nuclide migration for above report, so-called "base case", one option was chosen from many options, arbitrarily. In this report, the sensitivity of these options to nuclide migration calculation results was studied. As a result, there was no significant impact to nuclide migration although connectivity of channel and flow characteristics of the model slightly changed among different options. Based on above studies, we concluded that an option used for the base case was appropriate.

229 (Records 1-20 displayed on this page)